1. Field of Invention
The present invention relates to an inflator for use in a restraint system of a vehicle.
2. Description of Related Art
A hybrid inflator, in which a solid gas generating agent is used in combination with pressurized gas, is sometimes employed in a side impact protection airbag, wherein the gas generating agent needs to be burned promptly. Therefore, there is known an inflator having a structure in which a large number of granular gas generating agents are disposed in a combustion chamber.
The granular gas generating agents that fill the inside of the combustion chamber are ignited by an ignition device to start combustion. The gas generating agents need to be burned completely within the combustion chamber, but when a large number of granular gas generating agents are used, half-burned or unburned gas generating agents flow out of the combustion chamber, whereby outputs of the inflator fluctuate and the performance of the inflator is destabilized.
JP-A No. 2003-226222 discloses a hybrid inflator having a bottle 22 containing pressurized gas and a gas generator housing 32 containing a gas generating agent. In the gas generator housing 32, a granular gas generating agent 36 is stored, and it is ignited and burnt by an ignition device 34. A cap 44 formed, on a side surface, with a discharge hole 42 is attached to the pressurized gas chamber bottle 22, and combustion residues or fragments of a rupturable plate 40 are collected by this cap 44.
JP-A No. 2001-341610 discloses a hybrid inflator. A first gas generating chamber 120 and an internal space 103 filled with a pressurized medium are communicated with each other via a first communication hole 125 formed on a gas generator housing 105. This communication hole 125 allows the passage of combustion gas generated from a gas generating agent 124 and is formed into a size so as to be able to prevent the gas generating agent 124 from leaking to the outside.